1. Technical Field
The present disclosure relates to a turbomachine.
2. Description of the Related Art
In a known conventional turbomachine, a bearing that rotatably supports a rotating shaft to which an impeller is fixed is arranged on a front surface side of the impeller provided with a passage of a working fluid.
For example, as illustrated in FIG. 5A, Japanese Unexamined Patent Application Publication No. 2007-224868 describes a heat pump system 400, which includes a compressor 434 as a turbomachine. The heat pump system 400 uses water or water vapor as a working fluid. As illustrated in FIG. 5B, in the compressor 434, a rotor axis 480 to which an impeller 481 is connected is supported by bearings 451. Lubricating water supplied from a water supply line 453 absorbs frictional heat while functioning as a lubricant near the bearings 451, and is collected through a water drainage line 454.
As illustrated in FIG. 6, Japanese Unexamined Patent Application Publication No. 2011-133142 discloses an electric compressor 501 as a turbomachine. The electric compressor 501 is configured by integrating a compressor 501A and an electric motor 501B, and a coolant flows as the arrows illustrated in FIG. 6. Water is used as the coolant. The compressor 501A includes an impeller 511 with a rotating shaft 513, and a housing 512. The rotating shaft 513 is rotatably supported by bearings 526, 527, and 528. The housing 512 surrounds the impeller 511 and forms a passage for the coolant. For example, in the housing 512, a space 514 is formed around the periphery of the impeller 511. A coolant that flows into a coolant intake portion 512a from a coolant pipe 531 flows through a side portion of the impeller 511, which is on the side of the electric motor 501B, an intermediate cooler 529, a side portion of the impeller 511, which is on the opposite side of the electric motor 501B, and then through the space 514 and a coolant outlet 512b to flow into a coolant pipe 532.